Electrical household appliance for processing food comprising a safety device

ABSTRACT

An appliance includes a housing ( 1 ) containing a motor ( 2 ) whose output shaft ( 8 ) passes through the housing base ( 4 ) and drives in rotation a tool ( 16 ) housed in a bowl ( 9 ) locked on the housing and closed by a lid ( 12 ); and a safety device ( 25 ) having a vertical thruster ( 27 ) mounted sliding in the bowl ( 9 ) peripheral wall ( 30 ) and actuated by a cam ( 43 ) borne by the lid ( 12 ) so as to penetrate in an opening ( 39 ) provided in the base to be urged to actuate a switch controlling the motor. A rigid cover ( 49 ) is mounted on the base movable between an inoperative position wherein it conceals the base opening ( 39 ), when the bowl is not on the base ( 4 ), and an operative position wherein it clears the opening ( 39 ) by the action of an actuating member ( 51 ) borne by the bowl ( 9 ) when the latter is locked on the base ( 4 ).

CROSS REFERENCE TO RELATED APPLICATION

This is the 35 USC 371 national stage of International ApplicationPCT/FR98/01426 filed on Jul. 3, 1998, which designated the United Statesof America.

FIELD OF THE INVENTION

The present invention relates to an electric household appliance for theprocessing of foods, of the type particularly, but not exclusively, ofthe food processor type, which comprises a housing enclosing an electricmotor group and having a region forming a base whose upper surface istraversed by the output shaft of the motor group, and a bowl removablylocked on the base of the housing, closed to lock with a removablecover, and receiving a working tool adapted to be driven in rotation bythe motor shaft.

It relates more particularly to an apparatus of this type which moreovercomprises a safety device comprising a switch arranged in the supplycircuit of the motor, a pusher mounted vertically slidably in a recessprovided over all the height of the peripheral wall of the bowl, whoselower end is disposed in alignment with an opening provided in theperiphery of the base of the housing, when the bowl is locked on thebase, and whose upper end is adapted to be actuated by a cam carried bythe cover, when this latter is locked on the bowl in place, such thatthe pusher is lowered into the opening in the base, as well as a controlmechanism disposed in the housing, actuated by the pusher when it ispushed down into said opening, and controlling the opening of the switchto permit controlling the closure of the switch to permit supply of themotor.

BACKGROUND OF THE INVENTION

It is known that in such apparatus, it is important to avoid any contactof the hand with the rotating working tool, constituted generally by aslicing tool considered dangerous, so as to prevent accidents and, tothis end, the safety device of the above type with which the apparatusis provided is adapted to permit the operation of the motor only whenthe bowl is locked on the base of the housing, and when this bowl isitself locked by the cover.

In an electrical household appliance provided with a known safety deviceof this type, as described in FR-A-2 472 925, the opening of the baseadapted to the passage of the pusher opens outwardly when the bowl isnot in place on the base, and is closed in its lower portion by aflexible deformable membrane which is maintained by a lip formed on theinternal surface of the base, such that during locking of the cover onthe bowl once in place on the base, the cam carried by the coveractuates the pusher which is then pushed down into the opening of thebase, which pusher stretches the membrane and acts on the controlmechanism of the switch to cause closing of the electrical supplycircuit of the motor. However, this flexible membrane itself constitutesa costly member, difficult to emplace, adapted to come off, and subjectto deterioration with time, even to be torn by the repeated stretchingunder the action of the pusher, thus rendering the apparatus unusable.Moreover, the opening of the base being outward, and hence visible, whenthe bowl is not in place, the latter tends to attract the attention, inparticular of a child, and thus lead to accidental starting of the motorby stretching of the membrane with any object introduced into thisopening. Moreover, this opening in the base forms a food trap which istherefore apt to frustrate the control of the switch, and which isdifficult to clean.

SUMMARY OF THE INVENTION

The invention particularly has for its object to overcome thesedrawbacks and to provide an electrical household appliance, of the typedescribed above, in which the safety device operates perfectly and withhigh reliability.

According to the invention, the safety device comprises moreover a rigidpiece forming a cover which is movably mounted on the upper surface ofthe base of the housing between a rest position to which it isautomatically brought when the bowl is not in place on the base and inwhich it masks the opening of the base, and an active position in whichit is moved under the action of an actuating member carried by the bowlupon locking the latter on the base and in which it uncovers the openingof the base so as to permit passage of the pusher.

Thus, this rigid cover constitutes thereafter a truly robust mechanicalpiece, and hence is reliable, simpler, lost costly, easy to make andperfectly adapted to mass production. Moreover, the opening in the basebeing masked automatically by the cover in the rest position, when thebowl is not in place, this cover constitutes itself a member adapted todissuade any child from having access to the control mechanism of theswitch, and hence accidentally to start the motor, which especiallyincreases the safety of the device. This increase in safety is the morejustified as the movement of the cover permits uncovering the opening ofthe base which is itself subjected to the locking of the bowl on thebase.

According to a preferred embodiment, the cover is horizontally slidablymounted, in a direction transverse to the vertical axis of the motorshaft, in a recess which is provided in the upper surface of the baseextending to the peripheral edge of said base, and into which opens theopening of the base, said cover being slidably mounted the action of areturn spring which tends to return it to the rest position.

BRIEF DESCRIPTION OF THE DRAWINGS

The characteristics and advantages of the invention will become moreapparent from the description which follows, by way of non-limitingexample, with reference to the accompanying drawings, in which:

FIG. 1 is a schematic exploded view in vertical cross-section of ahousing, of a bowl and of a cover of an electrical household applianceaccording to the invention;

FIG. 2 is a view similar to FIG. 1, after locking the bowl on thehousing;

FIG. 3 is a view similar to FIG. 2, after locking the cover on the bowl;

FIG. 4 is a schematic perspective view, on an enlarged scale, of a coveron which is pivotally mounted a swinging lever;

FIG. 5 is a schematic perspective view, on a larger scale, of thisswinging lever; and

FIGS. 6, 7 and 8 are schematic plan views of a sliding control memberfor two switches, associated with the cover of FIG. 4, and adapted tooccupy three positions corresponding respectively to a rest position(FIG. 6) in which the bow is not locked on the base (FIG. 1), anintermediate position (FIG. 7) in which the bowl is locked on thehousing (FIG. 2), and a closure position (FIG. 8) in which the cover islocked on the bowl in place (FIG. 3).

DETAILED DESCRIPTION OF THE INVENTION

The electric household appliance for food processing, shown in FIGS. 1to 3, is a food processor comprising a housing or a base 1 having ageneral L shape which encloses an electric motor group 2 and which has aregion forming a base 4, for example of circular shape, whose uppersurface 6 is traversed by the vertical output shaft 8, along an axisXX′, of the motor group. On this base 4 is adapted to be mountedremovably a working bowl or receptacle 9 made of transparent plasticmaterial and provided with a handle 10. The bowl 9 is adapted to beclosed by the removable cover 12 provided with a hopper or feed tube 13into which are introduced the foodstuffs to be prepared.

The bowl 9 has a bottom wall 14 surmounted by a chimney 15 (FIG. 1) inwhich the output shaft 8 of the motor group 2 is engaged, and houses arotating working tool 16, such as a knife, which is fitted on thechimney 15 and which is coupled in rotation with the output shaft 8 ofthe motor group 2.

The bowl 9 is locked on the base 4 by means of a bayonet securementsystem and, to this end, the upper surface 6 of the base 4 has aprojecting disk 18 whose upper surface 19 is provided laterally,regularly about its periphery, with a plurality of notches 21, betterseen in FIG. 1, in which are inserted, upon rotation of the bowl 9, lugs22, better seen in FIG. 1, carried by the external surface of the bottomwall 14 of the bowl 9.

The cover 12 is locked on the bowl 9 by means of a securement system ofthe bayonet type, of which one of the elements is designated 23 in FIGS.1 and 2.

The food processor, FIGS. 1 to 3, moreover comprises a safety device,designated by the overall reference numeral 25 in FIGS. 1 and 3,comprising a pusher 27 mounted vertically slidably in a recess 29provided over all the height of the peripheral wall 30 of the bowl 9located facing the handle 10 of the bowl. The pusher 27 is slidablymounted against the force of a return spring 32 interposed between thehorizontal bearing surface 33 formed in the peripheral wall 30 of thebowl and a small horizontal wing 34 formed at right angles on the pusher27, in the lower part of this latter, see FIG. 1.

This pusher 27 has a lower end 36 which projects slightly through anopening 37 provided in the bottom of the peripheral wall 30 of the bowl9, as shown in FIG. 1, and which is disposed in line with an opening 39(FIGS. 2 and 3) provided in the periphery of the base 4, when the bowl 9is locked to the base 4 as shown in FIG. 2.

The pusher 27 also has an upper end 41 which is actuated by a cam 43carried by the cover 12, when this latter is locked on the bowl 9 inplace as shown in FIG. 3, such that the pusher 27 is received within theopening 39 of the base against its return spring 32, see FIG. 3.

The safety device 25, FIG. 3, also comprises a control mechanism 45,which will be described in detail later, disposed in the housing 1,actuated by the pusher 27 when it is received in the opening 39 (seeFIG. 3) and controlling the closing of a first switch, designated 47 inFIGS. 6 to 8, arranged in the supply circuit of the motor group.

According to the invention, this safety device moreover comprises arigid member forming a cover 49 which is movably mounted on the uppersurface 6 of the base 4 between a rest position (FIG. 1) to which it isautomatically brought when the bowl 9 is not in place on the base 4 andin which it masks the opening 39 in the base, and an active position(FIG. 2) to which it is moved under the action of an actuating member 51carried by the bowl 9 during locking of this latter on the base 4 and inwhich it uncovers the opening 39 in the base so as to permit the passageof the pusher 27.

According to a preferred embodiment of the invention, shown in FIGS. 1to 3, the cover 49 is in the general shape of a rectangular plate whichis slidably horizontally mounted, in a direction orthogonal to thevertical axis XX′ of the output shaft 8 of the motor group 2, in arecess 53 which is provided in the upper surface 6 of the base 4extending to the peripheral edge of this base, and into which opens theopening 39 in the base. This cover 49 is slidably mounted against theaction of a return spring 55 connected to the control mechanism 45 andadapted to return it to the rest position (FIG. 1).

In this embodiment, the base 4 has at its periphery, on the same side asthe cover 49, an integral vertically projecting bulge 57 having an upperportion forming a wing 58, for example of substantially semicircularshape as shown in broken lines on FIGS. 6 to 8, which raises it to acertain height relative to the upper surface 6 of the base 4. In thisembodiment, the cover 49 comprises itself, at its front end located atthe periphery of the base 4, a vertical wing 61, of a shape identical tothat of the wing 58, in this instance of substantially semicircularshape but inverted relative to the shape of the wing 58 as is seen inFIGS. 4 and 6 through 8, which raises it to the same height as this wing58 relative to the upper surface 6 of the base 4. Thus, when the cover49 is in the rest position (FIG. 1), the two wings 58 and 61 arelaterally secured to each other by their flat surface, thereby providinga seal for the housing 1; when the cover 49 slidably occupies, after ashort movement, of the order of 3 millimeters, its active position (FIG.2), the wing 61 of the cover 49 is then separated from the wing 58 ofthe bulge 57 so as to form between them a space 63 opening into therecess 53 of the cover and constituting itself the passage opening forthe pusher 27.

As shown in FIG. 1, one of the notches 21 of the disk 18 extends to thelevel of the cover 49 and has an opening 64 through the disk, whilst themember 51, adapted to actuate the cover 49 upon rocking of the bowl 9 onthe base 4, is in the form of a ramp provided on one of the lugs 22 ofthe bowl which is associated with this notch 21. The cover 49 carries atransverse rib 65 which is positioned in the opening 64 of this notch 21in a manner subjacent to the upper surface of the disk 18, when the bowl9 is not in place on the base 4, see FIG. 1. During locking by rotationof the bowl 9 on the base 4, the ramp 51 of the lug 22 of the bowl actson the rib 65 of the cover 49 thereby to effect sliding of the cover 49toward the center of the base 4, whose wing 61 separates from the wing58 of the bulge 57 to form the opening 63 for passage of the pusher 27,as shown in FIG. 2.

Preferably, the cover 49 as well as its wing 61 and its rib 65 aremolded of a single piece of rigid plastic material, as for examplepolypropylene.

It will here be noted that, when the bowl 9 is not in place on the base4 (FIG. 1), the passage opening for the pusher 27 is closed by contactof the two wings 58 and 61, and the rib 65 of the cover is hidden belowone of the lugs 21 of the disk 18, such that the cover 49 effectivelyprevents any child from manipulating this cover to make it slide in away that could accidentally start the motor, thereby increasing thesafety of the apparatus.

The control mechanism 45, FIGS. 1 to 3, comprises a swinging lever 68extending below the cover 49, of which one end 69 is located adjacentthe peripheral edge of the base 4 and is adapted to be actuated by thepusher 27 when the latter enters the opening 63 (FIG. 3), and whoseother end 70 is shaped as a small lever 72, better seen in FIG. 5, whichis articulatedly mounted on the upper surface of the cover 49, as seenin FIG. 4, through a recess 74 provided in the cover, by means of twopivots 76 constituting the swinging axis of the lever 68. This smalllever 72 is urged by an energy storage compression spring 78 which,before swinging of the lever 68, extends in a plane parallel to thelatter passing through the return spring 55 of the cover 49, as shown inFIG. 1.

This control mechanism 45 moreover comprises a control member 81, betterseen in FIGS. 6 to 8, which is traversed by the output shaft 8 of themotor group, and which is horizontally slidably mounted in the housing1, in the same direction as the cover 49. This control member 81 isassociated with a vertical tongue 83 carried by the lever 68, below thesmall lever 72, and is urged by the return spring 55.

As seen in FIGS. 6 to 8, the control member 81 has at its rear portiontwo horizontal fingers 85 and 86, parallel to each other and extendingperpendicularly to the direction of sliding of the control member 81, asindicated by the arrow F in FIGS. 6 and 7. The finger 85 is adapted tocoact with pushbutton 87 for the switch 47 for controlling the closingof the supply circuit of the motor group, whilst the finger 86 isadapted to coact simultaneously to the finger 85 with a pushbutton 89 ofa second switch 90, mounted reversely, and connected electrically to adevice (not shown) but known per se, to control the braking of theelectric motor.

By way of example, this braking device can be designed to cause to flowin the electric motor, if the latter is of the universal type, acountercurrent which creates a magnetic field tending to cause the motorto rotate reversely.

Preferably, the control member 81 and the two actuating fingers 85 and86 are molded of a single piece of plastic material.

When the bowl 9 is not in place on the base 4, as shown in FIG. 1, thecover 49 is in rest position in which the passage opening for the pusher27 is completely closed by the lateral contact of the two wings 56 and61, and the control member 81 also occupies a rest position, shown inFIG. 6, in which the two fingers 85 and 86 do not actuate the twoswitches 47 and 90, respectively.

During locking by rotation of the bowl 9 on the base 4, FIG. 2, thecover 49 slides to expose the opening 63 into which penetrates the lowerend 36 of the pusher 27; in the course of this sliding of the cover 49,the tongue 83 of the lever 68 articulatedly mounted on the cover 49causes the sliding of the control member 81 against the return spring55, in a first portion of the path of said approach, designated d inFIG. 6, at the end of which the two fingers 85 and 86 come into contactwith the respective pushbuttons 87 and 89 of the two switches 47 and 90,as shown in FIG. 7.

Then, in the course of locking by rotation the cover 12 on the bowl 9,as shown in FIG. 3, the pusher 27 enters the opening 63 under the actionof the cam 43 carried by the cover 12 and acts by its lower end 36 onthe end 69 of the lever 68 which thus swings in a clockwise directionabout the pivots 76 of the small lever 72. During swinging of the lever68, the tongue 83 which carries this latter causes a new sliding of thecontrol member 81, again against the return spring 55, on a secondportion of the path, designated d′ in FIG. 7, at the end of which thetwo fingers 85 and 86 depress the respective pushbuttons 87 and 89 ofthe two switches 47 and 90, as shown in FIG. 8. The switch 47 is thenclosed so as to permit a supply of the motor group 2, whilst the switch90 remains in an open position.

It should be emphasized here that the energy storage compression spring78 has a compressive force which is substantially greater than that ofthe return spring 55, so as to maintain pushed in the two respectivepushbuttons 87 and 89 of the two switches 47 and 90 at the end of thepath (d+d′) of said control member 81.

After processing the food, the user unlocks the cover 12 in the courseof which the cam 43 which it carries frees the pusher 27, which thenrises under the action of its return spring 32 and which gives rise to aswinging in the counterclockwise direction of the lever 68; the assemblyformed by the control member 81 and the cover 49 then slides in thereverse direction under the action of the return spring 55, along theportion of the path d′ (FIG. 7) at the end of which the two fingers 85and 86 free the respective pushbuttons 87 and 89 of the two switches 47and 90, as shown in FIG. 7. The switch 47 opens, whilst the switch 90passes from the closed condition in which it controls the braking deviceof the motor group 2, so as to stop very rapidly the rotation of thetool 16, and this even before the cover is completely withdrawn, therebypreventing any possibility of injury to the user.

The user then proceeds to unlock the bowl 9, then upon its withdrawal inthe course of which the control member 81 and the cover 49 again slidein the reverse direction, along this time the portion of the path d(FIG. 6), to return to their rest position, as illustrated in FIGS. 1and 6, in which the cover 49 closes the opening of the passage for thepusher 27.

It will be noted that the above description has been given withreference to a safety device for a food processor. Of course, thissafety device is equally applicable to any other electrical householdappliance for processing foods, such as in particular an electricchopper with a rotating knife, so designed that the housing enclosingthe motor group will be arranged below the working bowl.

What is claimed is:
 1. Electrical household appliance for processingfood, comprising a housing (1) enclosing an electric motor group (2) andhaving a region forming a base (4) whose upper surface (6) is traversedby the output shaft (8) of the motor group (2); a bowl (9) removablylocked on the base (4) of the housing, closed by locking a removablecover (12), and housing a working tool (16) adapted to be driven inrotation by the shaft (8) of the motor group; and a safety device (25)comprising a switch (47) arranged in the supply circuit of the motor, apusher (27) vertically slidably mounted in a recess (29) provided overall the height of the peripheral wall (30) of the bowl (9), whose lowerend (36) is disposed in line with an opening (39) provided in theperipheral of the base (4) of the housing, when the bowl (9) is lockedon the base, and whose upper end (41) is adapted to be actuated by a cam(43) carried by the cover (12), when this latter is locked in place onthe bowl, such that the pusher (27) enters the opening (39) of the base,as well as a control mechanism (45) disposed in the housing (1),actuated by the pusher (27) when it is in said opening (39), andcontrolling the closure of the switch (47) to permit supply of themotor, characterized in that the safety device (25) moreover comprises arigid member forming a cover (49) which is movably mounted on the uppersurface (6) of the base (4) of the housing between a rest position towhich it is automatically brought when the bowl (9) is not in place onthe base (4) and in which it covers the opening (39) in the base, and anactive position in which it is displaced under the action of anactuating member (51) carried by the bowl (9) during locking of thislatter onto the base (4) and in which it uncovers the opening (39) inthe base so as to permit passage of the pusher (27).
 2. Electricalhousehold appliance according to claim 1, characterized in that thecover (49) is horizontally slidably mounted, in a direction transverseto the vertical axis (XX′) of the shaft (8) of the motor group, in arecess (53) which is provided in the upper surface (6) of the base (4)extending to the peripheral edge of said base (4), and into which opensthe opening (39) of the base, said cover (49) being slidably mountedagainst the action of a return spring (55) which tends to return it to arest position.
 3. Electrical household appliance according to claim 2,characterized in that the base (4) has at its periphery, facing thecover (49), an invertically projecting bulge (57) having an upperportion forming a wing (58) rising to a certain height above the uppersurface (6) of the base (4), whilst the cover (49) comprises, at itsso-called front end located at the periphery of the base (4), a verticalwing (61) which rises to the same height as the wing (58) of the bulge(57) and which is of the same size as this wing (58) of the bulge, saidwing (61) of the cover (49) being in contact with the wing (58) of thebulge (57) when the cover (49) is in rest position and being separatedfrom this wing (58) of the bulge when the cover (49) occupies by slidingits active position so as to form between them a space (63) opening intothe recess (53) of the cover and constituting the opening (39) forpassage of the pusher (27).
 4. Electrical household appliance accordingto claim 2, in which the upper surface (6) of the base (4) of thehousing has a projecting disk (18) whose upper surface (19) is providedlaterally with notches (21) in which are inserted lugs (22) carried bythe wall of the base (14) of the bowl (9) during locking of this latteron the base, thereby constituting a bayonet lock, characterized in thatone (21) of the notches extends to the level of the cover (49) and thelug (22) with which it is associated has a ramp (51) constituting theactuating member and acting on a rib (65) which is formed on the cover(49) being positioned in said notch (21), subjacent to the upper surface(19) of the disc (18), so as to cause the cover (49) to slide toward itsactive position.
 5. Electrical household appliance according to claim 3,characterized in that the cover (49), the wing (61) and the rib (65) aremade of a single piece of rigid plastic material.
 6. Electricalhousehold appliance according to claim 2, characterized in that thecover (49) slides toward its active position along a short path, of theorder of 3 millimeters.
 7. Electrical household appliance according toclaim 2, characterized in that the control mechanism (45) comprises aswinging lever (68) extending below the cover (49) and being articulatedon this latter, of which one of the ends (69) is located adjacent theperipheral edge of the base (4) and is adapted to be actuated by thepusher (27) when the latter enters the opening (39) of the base, as wellas a control member (81) horizontally slidably mounted in the base (4),in the same transverse direction as the cover, associated with a tongue(83) carried by the lever (68) and being urged by a return spring (55)constituting the return spring of the cover, and adapted to slideagainst the force of said return spring (55), during a first phase,along a first portion of a so-called approach path (d), under the actionof the tongue (83) of the lever (68) when the cover (49) is displacedtoward its active position upon locking of the bowl (9) on the base (4),the cover (12) not being locked on the bowl (9), then during a secondphase, along a second portion (d′) of its path, under the action also ofthe tongue (83) of the lever (68) during swinging of this latter as aresult of the actuation of the end (69) of the lever by the pusher (27)during entry of this latter consecutive to the locking of the cover (12)on the bowl (9), said control member (81) having a first fingerprint(85) adapted to depress a pushbutton (87) of the switch (47) at the endof the path of this control member (81) so as to close the supplycircuit of the motor.
 8. Electrical household apparatus according toclaim 7, characterized in that the other end (70) of the lever (68) isshaped as a small lever (72) pivotally mounted on the upper surface ofthe cover (49), through a recess (74) provided in the cover (49), bymeans of a pivot (76) constituting the swinging axis of the lever (68),and which is urged by an energy accumulator compression spring (78)extending in the plane parallel to that passing through the returnspring (55) of the control member (81) and having a compressive forcewhich is substantially greater than that of the return spring (55) ofthe control member so as to maintain the pushbutton (87) of the switch(47) depressed at the end of movement of the control member (81). 9.Electrical household appliance according to claim 7, characterized inthat the control member (81) has a second finger (86) which coactssimultaneously with the first finger (85) with another switch (90) whichcan occupy either an open position at the end of the movement of thecontrol member (81), or a closed condition to which it is brought byreturn of the control member (81) and in which it controls the brakingmeans of the motor.
 10. Electrical household apparatus according toclaim 9, characterized in that the control member (81) and the first(85) and second (86) fingers are made of a single piece of plasticmaterial.